CarpetIOF5: Further development.

Make it work with multiple grid patches.
Break large file IOF5.cc into two, splitting off write.cc.
Some cleanup.
Introduce parameter "verbose".

darcs-hash:20051203052823-dae7b-fa36f867e8050de2940ba7ee179685872eda0864.gz

9 files changed, 420 insertions, 262 deletions

diff --git a/CarpetDev/CarpetIOF5/param.ccl b/CarpetDev/CarpetIOF5/param.ccl
index 1fae1f165..36663f2bf 100644
--- a/CarpetDev/CarpetIOF5/param.ccl
+++ b/CarpetDev/CarpetIOF5/param.ccl
@@ -1,5 +1,13 @@
 # Parameter definitions for thorn CarpetIOF5
 
+BOOLEAN verbose "Produce screen output while running"
+{
+} no
+
+BOOLEAN veryverbose "Produce much screen output while running"
+{
+} no
+
 SHARES: IO
 
 USES STRING  out_dir       AS IO_out_dir
diff --git a/CarpetDev/CarpetIOF5/schedule.ccl b/CarpetDev/CarpetIOF5/schedule.ccl
index 91f484a74..3f6209662 100644
--- a/CarpetDev/CarpetIOF5/schedule.ccl
+++ b/CarpetDev/CarpetIOF5/schedule.ccl
@@ -6,3 +6,9 @@ SCHEDULE CarpetIOF5_Startup AT startup AFTER IOUtil_Startup
 {
   LANG: C
 } "Startup routine"
+
+SCHEDULE CarpetIOF5_Init AT basegrid
+{
+  LANG: C
+  OPTIONS: global
+} "Initialisation routine"
diff --git a/CarpetDev/CarpetIOF5/src/IOF5.cc b/CarpetDev/CarpetIOF5/src/IOF5.cc
index 3833c1375..4c0fbf78c 100644
--- a/CarpetDev/CarpetIOF5/src/IOF5.cc
+++ b/CarpetDev/CarpetIOF5/src/IOF5.cc
@@ -13,16 +13,10 @@
 
 #include "carpet.hh"
 
-#include "coordinate_system.hh"
-#include "data_region.hh"
 #include "extending.hh"
 #include "file.hh"
-#include "physical_quantity.hh"
-#include "simulation.hh"
-#include "tensor_component.hh"
-#include "timestep.hh"
-#include "topology.hh"
 #include "utils.hh"
+#include "write.hh"
 
 
 
@@ -50,6 +44,9 @@ namespace CarpetIOF5 {
          int const convlevel,
          cGH * const cctkGH);
   
+  extern "C" void
+  CarpetIOF5_Init (CCTK_ARGUMENTS);
+  
   
   
   static int
@@ -60,6 +57,9 @@ namespace CarpetIOF5 {
                   char const * options,
                   void * ptr);
   
+  static int
+  base_10_digits (int number);
+  
   
   
   static int
@@ -79,33 +79,6 @@ namespace CarpetIOF5 {
                char const * varname,
                char const * alias);
   
-  static void
-  write_one_mglevel (cGH const * cctkGH,
-                     F5::timestep_t & timestep,
-                     int group,
-                     int variable);
-  
-  static void
-  write_global (cGH const * cctkGH,
-                F5::simulation_t & simulation,
-                int group,
-                int variable);
-
-  static void
-  write_one_reflevel (cGH const * cctkGH,
-                      F5::simulation_t & simulation,
-                      int group,
-                      int variable);
-  
-  static void
-  write_one_map (cGH const * cctkGH,
-                 F5::tensor_component_t & tensor_component,
-                 int group);
-  
-  static void
-  write_one_component (cGH const * cctkGH,
-                       F5::tensor_component_t & tensor_component);
-  
   
   
   static void
@@ -116,7 +89,9 @@ namespace CarpetIOF5 {
   int
   CarpetIOF5_Startup ()
   {
-    CCTK_INFO ("Startup");
+    DECLARE_CCTK_PARAMETERS;
+    
+    if (verbose) CCTK_INFO ("Startup");
     return extending_t::create (Setup);
   }
   
@@ -127,14 +102,31 @@ namespace CarpetIOF5 {
          int const convlevel,
          cGH * const cctkGH)
   {
+    DECLARE_CCTK_PARAMETERS;
+    
     assert (fleshconfig != 0);
-    CCTK_INFO ("Setup");
+    if (verbose) CCTK_INFO ("Setup");
     return extending_t::setup
       (cctkGH, OutputGH, TimeToOutput, TriggerOutput, OutputVarAs);
   }
   
   
   
+  void
+  CarpetIOF5_Init (CCTK_ARGUMENTS)
+  {
+    DECLARE_CCTK_ARGUMENTS;
+    DECLARE_CCTK_PARAMETERS;
+    
+    if (verbose) CCTK_INFO ("Init");
+
+    * next_output_iteration = 0;
+    * next_output_time = cctk_time;
+    * this_iteration = -1;
+  }
+  
+  
+  
   int
   OutputGH (cGH const * const cctkGH)
   {
@@ -142,7 +134,7 @@ namespace CarpetIOF5 {
     
     assert (cctkGH != 0);
     
-    CCTK_INFO ("OutputGH");
+    if (verbose) CCTK_INFO ("OutputGH");
     
     int ierr;
     
@@ -189,6 +181,21 @@ namespace CarpetIOF5 {
   
   
   int
+  base_10_digits (int number)
+  {
+    number = abs (number);
+    int digits = 1;
+    while (number >= 10)
+    {
+      number /= 10;
+      ++ digits;
+    }
+    return digits;
+  }
+  
+  
+  
+  int
   TimeToOutput (cGH const * const cctkGH,
                 int const variable)
   {
@@ -200,6 +207,7 @@ namespace CarpetIOF5 {
     
     assert (Carpet::is_level_mode());
     
+    if (verbose)
     {
       char * const fullname = CCTK_FullName(variable);
       CCTK_VInfo (CCTK_THORNSTRING, "TimeToOutput \"%s\"", fullname);
@@ -310,7 +318,7 @@ namespace CarpetIOF5 {
           (Carpet::mglevel, Carpet::reflevel, variable, cctk_iteration);
       }
     }
-    
+
     return should_output;
   }
   
@@ -325,6 +333,7 @@ namespace CarpetIOF5 {
     assert (cctkGH != 0);
     assert (variable >= 0 and variable < CCTK_NumVars());
     
+    if (verbose)
     {
       char * const fullname = CCTK_FullName(variable);
       CCTK_VInfo (CCTK_THORNSTRING, "TriggerOutput \"%s\"", fullname);
@@ -354,8 +363,11 @@ namespace CarpetIOF5 {
     assert (varname != 0);
     assert (alias != 0);
     
-    CCTK_VInfo (CCTK_THORNSTRING, "OutputVarAs \"%s\" \"%s\"",
-                varname, alias);
+    if (verbose)
+    {
+      CCTK_VInfo (CCTK_THORNSTRING, "OutputVarAs \"%s\" \"%s\"",
+                  varname, alias);
+    }
     
     int const variable = CCTK_VarIndex (varname);
     if (variable < 0)
@@ -376,8 +388,7 @@ namespace CarpetIOF5 {
     
     ostringstream filenamebuf;
     bool const use_IO_out_dir = strcmp (out_dir, "") == 0;
-    int const maxval = CCTK_nProcs (cctkGH);
-    int const digits = 1 + int (floor (log (double (maxval)) / log (10.0)));
+    int const digits = base_10_digits (CCTK_nProcs (cctkGH) - 1);
     filenamebuf << (use_IO_out_dir ? IO_out_dir : out_dir)
                 << "/"
                 << alias
@@ -393,21 +404,7 @@ namespace CarpetIOF5 {
     
     F5::file_t file (cctkGH, filename, do_truncate);
     
-    F5::timestep_t timestep (file, cctkGH->cctk_time);
-    
-    if (Carpet::is_meta_mode())
-    {
-      for (Carpet::mglevel_iterator mglevel_iter (cctkGH);
-           ! mglevel_iter.done();
-           mglevel_iter.step())
-      {
-        write_one_mglevel (cctkGH, timestep, group, variable);
-      }
-    }
-    else
-    {
-      write_one_mglevel (cctkGH, timestep, group, variable);
-    }
+    write::write_meta (cctkGH, file, group, variable);
     
     return Error_none;
   }
@@ -415,207 +412,6 @@ namespace CarpetIOF5 {
   
   
   void
-  write_one_mglevel (cGH const * const cctkGH,
-                     F5::timestep_t & timestep,
-                     int const group,
-                     int const variable)
-  {
-    CCTK_VInfo (CCTK_THORNSTRING,
-                "OutputVarAs/write_one_mglevel mglevel=%d", Carpet::mglevel);
-    
-    ostringstream namebuf;
-    namebuf << "convlevel=" << cctkGH->cctk_convlevel;
-    string const namestr = namebuf.str();
-    char const * const name = namestr.c_str();
-    F5::simulation_t simulation (timestep, name);
-    
-    int const grouptype = CCTK_GroupTypeI (group);
-    assert (grouptype >= 0);
-    switch (grouptype)
-    {
-    case CCTK_ARRAY:
-    case CCTK_SCALAR:
-      {
-        if (Carpet::do_global_mode)
-        {
-          write_global (cctkGH, simulation, group, variable);
-        }
-      }
-      break;
-    case CCTK_GF:
-      {
-        if (Carpet::is_global_mode())
-        {
-          for (Carpet::reflevel_iterator reflevel_iter (cctkGH);
-               ! reflevel_iter.done();
-               reflevel_iter.step())
-          {
-            write_one_reflevel (cctkGH, simulation, group, variable);
-          }
-        }
-        else
-        {
-          write_one_reflevel (cctkGH, simulation, group, variable);
-        }
-      }
-      break;
-    default:
-      assert (0);
-    }
-  }
-  
-  
-  
-  void
-  write_global (cGH const * const cctkGH,
-                F5::simulation_t & simulation,
-                int const group,
-                int const variable)
-  {
-    CCTK_INFO ("OutputVarAs/write_global");
-    
-    F5::unigrid_topology_t topology (simulation);
-    
-    int const grouptype = CCTK_GroupTypeI (group);
-    assert (grouptype >= 0);
-    assert (grouptype == CCTK_SCALAR or grouptype == CCTK_ARRAY);
-    
-    vect<CCTK_REAL, dim> level_origin, level_delta;
-    for (int d=0; d<dim; ++d)
-    {
-      level_origin[d] = 0.0;
-      level_delta[d]  = 1.0;
-    }
-    F5::Cartesian_coordinate_system_t coordinate_system
-      (topology, level_origin, level_delta);
-    
-    F5::physical_quantity_t physical_quantity (coordinate_system, group);
-    
-    F5::tensor_component_t tensor_component (physical_quantity, variable);
-    
-    int const myproc = CCTK_MyProc (cctkGH);
-    dh * const dd = Carpet::arrdata.at(group).at(0).dd;
-    bbox<int, dim> const & region
-      = dd->boxes.at(Carpet::mglevel).at(0).at(myproc).exterior;
-    
-    F5::data_region_t data_region (tensor_component, region);
-    
-    void const * const varptr = CCTK_VarDataPtrI (cctkGH, 0, variable);
-    assert (varptr != 0);
-    int const vartype = CCTK_VarTypeI (variable);
-    assert (vartype >= 0);
-    data_region.write (varptr, vartype);
-  }
-  
-  
-  
-  void
-  write_one_reflevel (cGH const * const cctkGH,
-                      F5::simulation_t & simulation,
-                      int const group,
-                      int const variable)
-  {
-    CCTK_VInfo (CCTK_THORNSTRING,
-                "OutputVarAs/write_one_reflevel reflevel=%d",
-                Carpet::reflevel);
-    
-    int const grouptype = CCTK_GroupTypeI (group);
-    assert (grouptype >= 0);
-    assert (grouptype == CCTK_GF);
-    
-    F5::mesh_refinement_topology_t topology
-      (simulation, Carpet::reflevel, Carpet::maxreflevels,
-       Carpet::spacereflevelfact, Carpet::maxspacereflevelfact);
-    
-    vect<CCTK_REAL, dim> level_origin, level_delta;
-    for (int d=0; d<dim; ++d)
-    {
-      DECLARE_CCTK_ARGUMENTS;
-      level_origin[d] = CCTK_ORIGIN_SPACE(d);
-      level_delta[d]  = CCTK_DELTA_SPACE(d);
-    }
-    F5::Cartesian_coordinate_system_t coordinate_system
-      (topology, level_origin, level_delta);
-    
-    F5::physical_quantity_t physical_quantity (coordinate_system, group);
-    
-    F5::tensor_component_t tensor_component (physical_quantity, variable);
-    
-    if (Carpet::is_level_mode())
-    {
-      for (Carpet::map_iterator map_iter (cctkGH, grouptype);
-           ! map_iter.done();
-           map_iter.step())
-      {
-        write_one_map (cctkGH, tensor_component, group);
-      }
-    }
-    else
-    {
-      write_one_map (cctkGH, tensor_component, group);
-    }
-  }
-  
-  
-  
-  void
-  write_one_map (cGH const * const cctkGH,
-                 F5::tensor_component_t & tensor_component,
-                 int const group)
-  {
-    CCTK_VInfo (CCTK_THORNSTRING,
-                "OutputVarAs/write_one_map map=%d", Carpet::map);
-    
-    if (Carpet::is_singlemap_mode())
-    {
-      int const grouptype = CCTK_GroupTypeI (group);
-      assert (grouptype >= 0);
-      
-      for (Carpet::component_iterator component_iter (cctkGH, grouptype);
-           ! component_iter.done();
-           component_iter.step())
-      {
-        write_one_component (cctkGH, tensor_component);
-      }
-    }
-    else
-    {
-      write_one_component (cctkGH, tensor_component);
-    }
-  }
-  
-  
-  
-  void
-  write_one_component (cGH const * const cctkGH,
-                       F5::tensor_component_t & tensor_component)
-  {
-    CCTK_VInfo (CCTK_THORNSTRING,
-                "OutputVarAs/write_one_component component=%d",
-                Carpet::component);
-    
-    gh * const hh = Carpet::vhh.at(Carpet::map);
-    if (hh->is_local (Carpet::reflevel, Carpet::component))
-    {
-      dh * const dd = Carpet::vdd.at(Carpet::map);
-      bbox<int, dim> const & region
-        = (dd->boxes.at(Carpet::mglevel).at(Carpet::reflevel)
-           .at(Carpet::component).exterior);
-      
-      F5::data_region_t data_region (tensor_component, region);
-      
-      int const variable = tensor_component.get_variable();
-      void const * const varptr = CCTK_VarDataPtrI (cctkGH, 0, variable);
-      assert (varptr != 0);
-      int const vartype = CCTK_VarTypeI (variable);
-      assert (vartype >= 0);
-      data_region.write (varptr, vartype);
-    }
-  }
-  
-  
-  
-  void
   WriteParameters (F5::file_t & file)
   {
     hid_t const parameter_group
diff --git a/CarpetDev/CarpetIOF5/src/data_region.cc b/CarpetDev/CarpetIOF5/src/data_region.cc
index d19700cc3..66f61e8cc 100644
--- a/CarpetDev/CarpetIOF5/src/data_region.cc
+++ b/CarpetDev/CarpetIOF5/src/data_region.cc
@@ -5,6 +5,8 @@
 
 #include "cctk.h"
 
+#include "carpet.hh"
+
 #include "data_region.hh"
 #include "utils.hh"
 
@@ -27,7 +29,8 @@ namespace CarpetIOF5 {
       assert (! region.empty());
       
       ostringstream namebuf;
-      namebuf << "region=" << m_region;
+      namebuf << "map=" << Carpet::map << " "
+              << "region=" << m_region;
       string const namestr = namebuf.str();
       char const * const name = namestr.c_str();
       assert (name != 0);
@@ -44,7 +47,7 @@ namespace CarpetIOF5 {
         = (region.shape() / region.stride()).reverse();
       m_dataspace = H5Screate_simple (dim, & dims [0], & dims [0]);
       assert (m_dataspace >= 0);
-
+      
       m_dataset
         = H5Dcreate (m_tensor_component.get_hdf5_tensor_component(), name,
                      hdf5_datatype, m_dataspace, m_properties);
diff --git a/CarpetDev/CarpetIOF5/src/make.code.defn b/CarpetDev/CarpetIOF5/src/make.code.defn
index 05dce8360..40fab33c2 100644
--- a/CarpetDev/CarpetIOF5/src/make.code.defn
+++ b/CarpetDev/CarpetIOF5/src/make.code.defn
@@ -11,7 +11,8 @@ SRCS =	IOF5.cc					\
         tensor_component.cc			\
         timestep.cc 				\
         topology.cc 				\
-        utils.cc
+        utils.cc				\
+        write.cc
 
 # Subdirectories containing source files
 SUBDIRS = 
diff --git a/CarpetDev/CarpetIOF5/src/physical_quantity.cc b/CarpetDev/CarpetIOF5/src/physical_quantity.cc
index fa5fa00d5..bd1ee4f7c 100644
--- a/CarpetDev/CarpetIOF5/src/physical_quantity.cc
+++ b/CarpetDev/CarpetIOF5/src/physical_quantity.cc
@@ -22,6 +22,10 @@ namespace CarpetIOF5 {
       
       char * const name = CCTK_GroupName (group);
       assert (name != 0);
+      for (char * p = name; * p; ++ p)
+      {
+        * p = static_cast<char> (tolower (* p));
+      }
       
       m_hdf5_physical_quantity
         = open_or_create_group (m_coordinate_system
diff --git a/CarpetDev/CarpetIOF5/src/timestep.cc b/CarpetDev/CarpetIOF5/src/timestep.cc
index 37d37cd20..746c2fd6f 100644
--- a/CarpetDev/CarpetIOF5/src/timestep.cc
+++ b/CarpetDev/CarpetIOF5/src/timestep.cc
@@ -42,7 +42,7 @@ namespace CarpetIOF5 {
       {
         // Create a string from the time without losing information
         int const precision = numeric_limits<CCTK_REAL>::digits10 + 2;
-        buf << setprecision (precision) << "T=" << time;
+        buf << setprecision (precision) << "t=" << time;
       }
       m_name = buf.str();
       
diff --git a/CarpetDev/CarpetIOF5/src/write.cc b/CarpetDev/CarpetIOF5/src/write.cc
new file mode 100644
index 000000000..bba4523f9
--- /dev/null
+++ b/CarpetDev/CarpetIOF5/src/write.cc
@@ -0,0 +1,284 @@
+#include <sstream>
+
+#include "cctk.h"
+#include "cctk_Arguments.h"
+#include "cctk_Parameters.h"
+
+#include "carpet.hh"
+  
+#include "data_region.hh"
+#include "file.hh"
+#include "simulation.hh"
+#include "tensor_component.hh"
+#include "timestep.hh"
+#include "topology.hh"
+#include "write.hh"  
+
+
+  
+namespace CarpetIOF5 {
+  
+  namespace write {
+    
+    void
+    write_meta (cGH const * const cctkGH,
+                F5::file_t & file,
+                int const group,
+                int const variable)
+    {
+      DECLARE_CCTK_PARAMETERS;
+      
+      if (verbose or veryverbose)
+      {
+        CCTK_VInfo (CCTK_THORNSTRING,
+                    "OutputVarAs/write_meta");
+      }
+      
+      F5::timestep_t timestep (file, cctkGH->cctk_time);
+      
+      if (Carpet::is_meta_mode())
+      {
+        for (Carpet::mglevel_iterator mglevel_iter (cctkGH);
+             ! mglevel_iter.done();
+             mglevel_iter.step())
+        {
+          write_one_mglevel (cctkGH, timestep, group, variable);
+        }
+      }
+      else
+      {
+        write_one_mglevel (cctkGH, timestep, group, variable);
+      }
+    }
+    
+    
+    
+    void
+    write_one_mglevel (cGH const * const cctkGH,
+                       F5::timestep_t & timestep,
+                       int const group,
+                       int const variable)
+    {
+      DECLARE_CCTK_PARAMETERS;
+      
+      if (verbose or veryverbose)
+      {
+        CCTK_VInfo (CCTK_THORNSTRING,
+                    "OutputVarAs/write_one_mglevel mglevel=%d",
+                    Carpet::mglevel);
+      }
+      
+      ostringstream namebuf;
+      namebuf << "convlevel=" << cctkGH->cctk_convlevel;
+      string const namestr = namebuf.str();
+      char const * const name = namestr.c_str();
+      F5::simulation_t simulation (timestep, name);
+      
+      int const grouptype = CCTK_GroupTypeI (group);
+      assert (grouptype >= 0);
+      switch (grouptype)
+      {
+      case CCTK_ARRAY:
+      case CCTK_SCALAR:
+        {
+          if (Carpet::do_global_mode)
+          {
+            write_global (cctkGH, simulation, group, variable);
+          }
+        }
+        break;
+      case CCTK_GF:
+        {
+          if (Carpet::is_global_mode())
+          {
+            for (Carpet::reflevel_iterator reflevel_iter (cctkGH);
+                 ! reflevel_iter.done();
+                 reflevel_iter.step())
+            {
+              write_one_reflevel (cctkGH, simulation, group, variable);
+            }
+          }
+          else
+          {
+            write_one_reflevel (cctkGH, simulation, group, variable);
+          }
+        }
+        break;
+      default:
+        assert (0);
+      }
+    }
+    
+    
+    
+    void
+    write_global (cGH const * const cctkGH,
+                  F5::simulation_t & simulation,
+                  int const group,
+                  int const variable)
+    {
+      DECLARE_CCTK_PARAMETERS;
+      
+      if (verbose or veryverbose)
+      {
+        CCTK_INFO ("OutputVarAs/write_global");
+      }
+      
+      F5::unigrid_topology_t topology (simulation);
+      
+      int const grouptype = CCTK_GroupTypeI (group);
+      assert (grouptype >= 0);
+      assert (grouptype == CCTK_SCALAR or grouptype == CCTK_ARRAY);
+      
+      vect<CCTK_REAL, dim> level_origin, level_delta;
+      for (int d=0; d<dim; ++d)
+      {
+        level_origin[d] = 0.0;
+        level_delta[d]  = 1.0;
+      }
+      F5::Cartesian_coordinate_system_t coordinate_system
+        (topology, level_origin, level_delta);
+      
+      F5::physical_quantity_t physical_quantity (coordinate_system, group);
+      
+      F5::tensor_component_t tensor_component (physical_quantity, variable);
+      
+      int const myproc = CCTK_MyProc (cctkGH);
+      dh * const dd = Carpet::arrdata.at(group).at(0).dd;
+      bbox<int, dim> const & region
+        = dd->boxes.at(Carpet::mglevel).at(0).at(myproc).exterior;
+      
+      F5::data_region_t data_region (tensor_component, region);
+      
+      void const * const varptr = CCTK_VarDataPtrI (cctkGH, 0, variable);
+      assert (varptr != 0);
+      int const vartype = CCTK_VarTypeI (variable);
+      assert (vartype >= 0);
+      data_region.write (varptr, vartype);
+    }
+    
+    
+    
+    void
+    write_one_reflevel (cGH const * const cctkGH,
+                        F5::simulation_t & simulation,
+                        int const group,
+                        int const variable)
+    {
+      DECLARE_CCTK_PARAMETERS;
+      
+      if (verbose or veryverbose)
+      {
+        CCTK_VInfo (CCTK_THORNSTRING,
+                    "OutputVarAs/write_one_reflevel reflevel=%d",
+                    Carpet::reflevel);
+      }
+      
+      int const grouptype = CCTK_GroupTypeI (group);
+      assert (grouptype >= 0);
+      assert (grouptype == CCTK_GF);
+      
+      F5::mesh_refinement_topology_t topology
+        (simulation, Carpet::reflevel, Carpet::maxreflevels,
+         Carpet::spacereflevelfact, Carpet::maxspacereflevelfact);
+      
+      if (Carpet::is_level_mode())
+      {
+        for (Carpet::map_iterator map_iter (cctkGH, grouptype);
+             ! map_iter.done();
+             map_iter.step())
+        {
+          write_one_map (cctkGH, topology, group, variable);
+        }
+      }
+      else
+      {
+        write_one_map (cctkGH, topology, group, variable);
+      }
+    }
+    
+    
+    
+    void
+    write_one_map (cGH const * const cctkGH,
+                   F5::topology_t & topology,
+                   int const group,
+                   int const variable)
+    {
+      DECLARE_CCTK_PARAMETERS;
+      
+      if (verbose or veryverbose)
+      {
+        CCTK_VInfo (CCTK_THORNSTRING,
+                    "OutputVarAs/write_one_map map=%d", Carpet::map);
+      }
+      
+      vect<CCTK_REAL, dim> level_origin, level_delta;
+      for (int d=0; d<dim; ++d)
+      {
+        DECLARE_CCTK_ARGUMENTS;
+        level_origin[d] = CCTK_ORIGIN_SPACE(d);
+        level_delta[d]  = CCTK_DELTA_SPACE(d);
+      }
+      F5::Cartesian_coordinate_system_t coordinate_system
+        (topology, level_origin, level_delta);
+      
+      F5::physical_quantity_t physical_quantity (coordinate_system, group);
+      
+      F5::tensor_component_t tensor_component (physical_quantity, variable);
+      
+      if (Carpet::is_singlemap_mode())
+      {
+        int const grouptype = CCTK_GroupTypeI (group);
+        assert (grouptype >= 0);
+        
+        for (Carpet::component_iterator component_iter (cctkGH, grouptype);
+             ! component_iter.done();
+             component_iter.step())
+        {
+          write_one_component (cctkGH, tensor_component);
+        }
+      }
+      else
+      {
+        write_one_component (cctkGH, tensor_component);
+      }
+    }
+    
+    
+    
+    void
+    write_one_component (cGH const * const cctkGH,
+                         F5::tensor_component_t & tensor_component)
+    {
+      DECLARE_CCTK_PARAMETERS;
+      
+      if (verbose or veryverbose)
+      {
+        CCTK_VInfo (CCTK_THORNSTRING,
+                    "OutputVarAs/write_one_component component=%d",
+                    Carpet::component);
+      }
+      
+      gh * const hh = Carpet::vhh.at(Carpet::map);
+      if (hh->is_local (Carpet::reflevel, Carpet::component))
+      {
+        dh * const dd = Carpet::vdd.at(Carpet::map);
+        bbox<int, dim> const & region
+          = (dd->boxes.at(Carpet::mglevel).at(Carpet::reflevel)
+             .at(Carpet::component).exterior);
+        
+        F5::data_region_t data_region (tensor_component, region);
+        
+        int const variable = tensor_component.get_variable();
+        void const * const varptr = CCTK_VarDataPtrI (cctkGH, 0, variable);
+        assert (varptr != 0);
+        int const vartype = CCTK_VarTypeI (variable);
+        assert (vartype >= 0);
+        data_region.write (varptr, vartype);
+      }
+    }
+    
+  } // namespace write
+  
+} // namespace CarpetIOF5
diff --git a/CarpetDev/CarpetIOF5/src/write.hh b/CarpetDev/CarpetIOF5/src/write.hh
new file mode 100644
index 000000000..08a45ef9b
--- /dev/null
+++ b/CarpetDev/CarpetIOF5/src/write.hh
@@ -0,0 +1,56 @@
+#ifndef WRITE_HH
+#define WRITE_HH
+
+#include "cctk.h"
+
+#include "file.hh"
+#include "simulation.hh"
+#include "tensor_component.hh"
+#include "timestep.hh"
+#include "topology.hh"
+
+
+
+namespace CarpetIOF5 {
+  
+  namespace write {
+    
+    void
+    write_meta (cGH const * cctkGH,
+                F5::file_t & file,
+                int group,
+                int variable);
+    
+    void
+    write_one_mglevel (cGH const * cctkGH,
+                       F5::timestep_t & timestep,
+                       int group,
+                       int variable);
+    
+    void
+    write_global (cGH const * cctkGH,
+                  F5::simulation_t & simulation,
+                  int group,
+                  int variable);
+    
+    void
+    write_one_reflevel (cGH const * cctkGH,
+                        F5::simulation_t & simulation,
+                        int group,
+                        int variable);
+    
+    void
+    write_one_map (cGH const * cctkGH,
+                   F5::topology_t & topology,
+                   int group,
+                   int variable);
+    
+    void
+    write_one_component (cGH const * cctkGH,
+                         F5::tensor_component_t & tensor_component);
+    
+  } // namespace write
+  
+} // namespace CarpetIOF5
+
+#endif  // #ifndef WRITE_HH